3.7 Cross-reference commands

SLIME’s cross-reference commands are based on the support provided
by the Lisp system, which varies widely between Lisps. For systems
with no built-in XREF support SLIME queries a portable
XREF package, which is taken from the CMU AI
Repository and bundled with SLIME.

Each command operates on the symbol at point, or prompts if there is
none. With a prefix argument they always prompt. You can either enter
the key bindings as shown here or with the control modified on the
last key, See Key bindings.

There are also “List callers/callees” commands. These operate by
rummaging through function objects on the heap at a low-level to
discover the call graph. They are only available with some Lisp
systems, and are most useful as a fallback when precise XREF
information is unavailable.